JERUSALEM -- Ahead of another visit this week by U.S. Secretary of State John F. Kerry, reports that he plans to present a framework for peace to Israeli and Palestinian leaders are causing growing unrest among Israeli opponents of a two-state solution.

Early Tuesday, vandals torched cars and property in the Palestinian village of Jilazoun, spray-painting walls with messages warning that “much blood will be spilled” over Judea and Samaria, the biblical term for the West Bank. The perpetrators, suspected to be Jewish extremists, left another message: “Regards to John Kerry.”

The attack came hours after Israel released 26 Palestinian prisoners from jail, the third of four groups it promised to free as part of peace talks restarted during the summer.

Publicly, officials on both sides sound skeptical about the prospects for progress, accusing each other of obstructing the talks. But the absence of solid information from the closed-door negotiations and Kerry’s frequent visits to the region are making Israel’s right wing nervous.

This week, a group of settlers organizations launched a publicity campaign against Prime Minister Benjamin Netanyahu’s government, warning that it was playing with fire. An Internet ad depicted Kerry, together with Israeli, Palestinian and American negotiators, in a matchbox engulfed in flames. (link in Hebrew)

“Oslo III is already here,” the ad warns, referring to the Oslo peace accords signed in two parts in the 1990s. “When it catches fire, it will be too late,” it cautions, calling on leaders to “extinguish” the U.S.-led push for an agreement.

Hawkish politicians, including from Netanyahu’s own Likud Party, are also heating things up. After the Palestinians protested U.S. proposals that they said favored Israeli security demands in the Jordan Valley, Likud lawmaker Miri Regev proposed a law extending Israeli authority over Jewish communities in that part of the West Bank, a move that would effectively annex the strategic area along the border with Jordan.

Her bill cleared a preliminary discussion in a legislative committee Sunday but isn’t likely to pass, as ministers including Justice Minister Tzipi Livni, the government’s chief negotiator in the peace talks, are opposing it. Netanyahu also objects to the bill but has not gone to great lengths to quash it, observers note.

The proposed legislation infuriated Palestinians, who Tuesday moved their weekly Cabinet meeting from Ramallah to the Jordan Valley in a show of protest.

Palestinian Authority President Mahmoud Abbas declared Palestinian control of the Jordan valley a “red line,” and negotiator Saeb Erekat said Palestinians should respond by seeking statehood from the United Nations.

Israeli hard-liners were also digging in ahead of Kerry’s expected arrival Thursday, announcing they would dedicate a new neighborhood in a Jordan Valley settlement at a ceremony to be attended by activists and politicians, including Interior Minister Gideon Saar, a Likud member.

Likud’s position on the Jordan Valley is clear, Deputy Defense Minister Danny Danon stated this week. It is an integral part of Israel, and anyone who disagrees “is apparently in the wrong party,” he said, sending a barb the prime minister’s way.

Netanyahu could eventually find himself in a position similar to that of Prime Minister Ariel Sharon, who quit Likud and formed a new party in the face of resistance to his plan to withdraw from the Gaza Strip in 2005.

In theory, Netanyahu could do the same, political analyst Hanan Kristal told Israel Radio. “The big question is whether he has truly crossed the Rubicon,” he said.

Abraham Diskin, a veteran political scientist from the Hebrew University of Jerusalem, likened Netanyahu to “an overloaded juggler” trying to reconcile his intention to advance the peace process and avoid a rift with the United States with the political pressure from his party and government, as well as his own red lines.

“The bottom line is that Netanyahu has lost control of his party,” Diskin said.

Opposition member Shelly Yachimovich dismissed the notion that Netanyahu was trying to rein in unruly party members as an act intended to maintain the appearance of negotiating.

JERUSALEM-- Israeli military forces launched a series of attacks in the Gaza Strip on Tuesday in response to suspected Palestinian sniper fire that killed an Israeli civilian doing repair work on the border fence, military authorities said.